def guess(number):
    i = 0
    original_number = number
    while number != 1:
        if number % 2 == 0:
            number = number / 2
        else:
            number = number * 3 + 1
        i += 1
    print(f"{original_number}经过{i}次变换后回到1")
num = int(input("请输入一个大于1的正整数:"))
guess(num)
